Maine Chapter

Our Work In Maine

The Problem

The loss of the American chestnut tree (Castanea dentata) is often cited as one of the worst ecological disasters in modern times. An estimated 4 billion chestnut trees, one in four trees in our eastern forests, were killed as a result of a fungus, the chestnut blight (Cryphonectria parasitica).  This fungus was native to Asia but was accidentally brought to New York in 1904. It quickly spread and within a few decades most American chestnuts lay dead on the ground. The species and communities that depended upon them for food and shelter were diminished in turn.

When the fungus girdles and kills the trunk of the tree, the root often survives and sprouts in the forest understory. The tree’s ability to root sprout is the only reason wild chestnuts persist in our forests today. The sprouts grow into trees but rarely mature to the point of flowering and producing seeds. Thus, the blight prevents the American chestnut from reproducing and evolving as a species. Without our intervention the chestnut is unlikely to reclaim its former territory and its outsized role in forest ecology and human culture.

Our Mission

The mission of The American Chestnut Foundation (TACF) and its 16 chapters is to return the iconic American chestnut to its native range. In our attempts to restore this species, we are blazing a trail to guide future restoration efforts for other trees in trouble.

Our Approach

The goal of the TACF breeding program has been to move the gene for resistance, which occurs in the Chinese chestnut, into the American chestnut’s genome. This goal has been approached in two ways: a standard back-cross breeding program and genetic engineering.

Backcross Breeding

The Maine Chapter of TACF is one of many chapters engaged in a long-term back-cross breeding program with support from TACF’s staff and research farm in Meadowview, VA. Employing Maine wild chestnuts as mother trees, we aim to produce a blight resistant tree that is well adapted to Maine growing conditions.

We have long expected to see blight resistance work its way into the American Chestnut genome but this goal has remained elusive.  Modern gene technology recently revealed that the combination of genes that confer resistance is more complicated and harder to pass along through standard back-cross breeding. After growing and tending hundreds of thousands of young chestnut trees over two decades, we have yet to produce a reliably blight tolerant tree that retains its distinctive American features. We have, however, learned a lot about chestnut trees and identified certain trees that appear somewhat less vulnerable to severe blight infection.

Biotechnology

A transgenic approach to blight tolerance has been underway almost as long as the back-cross breeding program. One benefit of this approach is that the American chestnut genome does not become contaminated by the many extraneous Chinese chestnut genes that come with traditional breeding.

Managed by the State University of New York at Syracuse (SUNY Syracuse), transgenic research to date has been focused on moving a gene found in wheat, bananas, strawberries and many other human foods, into the American chestnut. This gene is effective at protecting plant tissues from invasion by fungi that produce oxalic acid as part of their infection process. The gene produces an enzyme that breaks down the acid. It seems to confer some resistance to the fungus that causes chestnut blight.

Tom Klak, from the University of New England (UNE) in Biddeford Maine, has devoted years to advancing this approach. Dr.Klak has developed ways to speed the growth rate of chestnut seedlings in the greenhouse to produce pollen much faster. In 2021-2023, with help from his students, TACF volunteers, and generous land owners, Tom established a transgenic research orchard in Cape Elizabeth Maine, under special permit by federal regulators, to monitor the performance of the Darling 58 transgenic chestnut under field conditions.

After careful study Dr. Klak and Dr. Han Tan from the University of Maine at Orono, reported some problems with Darling 58. Their lab and field observations, along with reports by other researchers, led to the decision by TACF in December 2023 to pull its support for deregulation of the Darling line for restoration purposes. To read more details go to https://tacf.org/darling-58-performance/

Although this is a setback for advancement of the Darling 58 tree, much has been learned along the way that holds promise for development of a new and better transgenic chestnut. The technology and tools for understanding and testing for blight resistance have advanced dramatically in recent years. These hold the promise for more efficient progress in developing a blight resistant chestnut.   

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Celebrate the legacy of Rex Mann—forester, storyteller, and passionate champion for the American chestnut—with this limited edition Leave Tracks t-shirt.

Rex devoted his life to restoring forests and inspiring others to care for the land. Now, you can honor his memory and help carry his mission forward.

🌳 100% of the proceeds from every shirt go to The American Chestnut Foundation (THANK YOU!), supporting the work Rex believed in so deeply.

👉 Pre-order now through August 2: scottmann.com/store/Leave-Tracks-In-Honor-of-Rex-Mann-PREORDER-p768130686

Let’s keep walking the trail Rex helped blaze.
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Celebrate the legacy of Rex Mann—forester, storyteller, and passionate champion for the American chestnut—with this limited edition Leave Tracks t-shirt.Rex devoted his life to restoring forests and inspiring others to care for the land. Now, you can honor his memory and help carry his mission forward.🌳 100% of the proceeds from every shirt go to The American Chestnut Foundation (THANK YOU!), supporting the work Rex believed in so deeply.👉 Pre-order now through August 2: https://scottmann.com/store/Leave-Tracks-In-Honor-of-Rex-Mann-PREORDER-p768130686Let’s keep walking the trail Rex helped blaze.

We’re excited to share a new animated video explaining TACF’s RGS program! ... See MoreSee Less

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1 CommentComment on Facebook

Transgenic American Chestnuts are still a much better option. The product of this method will always be a hybrid and that should not be the goal.

One of the greatest ecological disasters the US has ever seen. Chestnut blight wiped out the American chestnut tree in less than 50 years.⁠
A tree that once made up nearly 25% of the eastern forests was reduced to a functionally extinct species.⁠

The Asian fungus Cryphonectria parasitica was accidentally introduced into the United States in the late 1800s. While a few diseased chestnuts were noted in the 1880s and 90s, it wasn't until 1904 that the pathogen was identified in New York City. From that point, the blight spread rapidly. By 1950 the entire range had been consumed.⁠

The fungus causes cankers that spread around the trunk of the tree, girdling it and killing everything above ground. Many root systems still survive today and continue to send up shoots, but these also eventually succumb to blight. Because American chestnuts rarely survive long enough to reproduce, the species is considered functionally extinct.⁠

The American Chestnut Foundation is working to develop blight-resistant American chestnuts that can be used to restore this iconic tree to its native range. Learn more at tacf.org/about-us (link in bio)
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140 CommentsComment on Facebook

I think I may have found an American Chestnut tucked away in a backyard

Incredibly important work…it was such a travesty for our forests!

The trees seem to still be intact outside their range in isolated areas. Theres a few large ones here in central Michigan on a peninsula and again on the Leelenau peninsula in the nw lower peninsula. I keep seeing people chime in about adult trees here and there. Seems like there's hope!

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Just another day working to bring back the American chestnut. 🌰 ... See MoreSee Less

6 CommentsComment on Facebook

Yikes. Most of those pictures look like very Chinese hybrids.

I have a very old American chestnut tree that has the blight . It gets chocked off then gets new growth. It got a lot of wind this year and lost a lot of the blooms. It produces nuts still . Does anyone want to get a start of the new fruit before I move or pass way ? I’m afraid the new owners will destroy it. This was the only reason I wanted this house in the late 80’s .

Hope you are successful!!!

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Especially if you're under a canopy of American chestnuts... ... See MoreSee Less

Especially if youre under a canopy of American chestnuts...

6 CommentsComment on Facebook

Unless, of course, it's fall. Then the chestnut seed pods are falling from the trees and creating a floor covered in pins and needles so sharp that it puts sweetgum to shame. You wouldn't want to be laying under the chestnut canopy then!

I live in Barboursville, WV and wanted to know if i can buy a seedling or how i go about acquiring one! Thank you!

The SHADE TREE COMMISSION in NEW PALTZ New York is interested in planting some CHESTNUT trees on Chestnut Street (Rt. 32). We would like to receive help from you if possible. New Paltz is a historic town and in the past there were MANY Chestnut trees here, Presently there is only ONE Chestnut tree which I grew from the nut of an elegant, large tree when it was sadly cut down. If there are any Chestnut trees available, or if you have any suggestion that might help us in this quest we would be greatful. Thank you for your attention., Shelly Ottens (moc.oohay@obobnyllehsih)

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(828) 281-0047

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